The present invention relates to a support structure for a signature loader or other such loading machine. In particular the invention relates to a support structure for a signature loader which is adjustable to enable the signatures to be discharged from the loader with one side disposed in correspondence with a predetermined vertical plane, independently of the form and dimensions (thickness, width etc.) of the signatures.
In the process of binding books, the signatures, that is to say the printed sheets which have been folded, are transferred to an automatic feeder which conveys them to subsequent operating machines. In order to transfer the signatures onto the feeder there are currently employed so-called "signature loaders" provided with adjustable margining devices which can be adjusted symmetrically and which are arranged to supply the said sheet feeder via an intermediate conveyor belt. Currently available signature loaders are equipped in such a way as to be able to collect signatures of various different shapes and sizes, but it is a disadvantage of such loaders that the symmetrical adjustment maintains the mid-line of the signatures in register with the longitudinal axis of the loader, which means that the position of the lateral edges of the signatures as they are discharged from the loader will be different for signatures of different sizes. This makes the subsequent feeding operation rather complex if the feeder is feeding a certain type of binding machine which has to receive the signatures with a given edge in a predetermined lateral position in order that these shall line up properly with the various working parts of the binding machine.